1. Field of the Invention
This invention relates to a disposable syringe having particular application to vacuum tube phlebotomy and comprising means by which to shield an associated hypodermic needle to reduce the possibility of an accidental, and possibly life threatening, needle strike and the spread of contagious disease.
2. Prior Art
Hypodermic syringes are used for a variety of purposes. By way of a first example, the syringe may be used for vacuum tube phlebotomy, where samples of the patient's blood are successively drawn into respective evacuated tubes by way of a double ended hypodermic needle. In a second example, the syringe may be used to expulse fluid medication to a patient by way of a single ended hypodermic needle and a conventional injection procedure. In either example, the syringe may be used to treat a patient having a communicable disease. Prior to disposal of the syringe, the hypodermic needle thereof is sometimes broken to prevent reuse. Health care workers are especially susceptible to accidental and potentially infectious needle strikes due to the careless handling or breaking of the needle and disposing of the syringe after use. The resulting mini-accidents caused by an accidental needle strike typically require a blood test for such diseases as AIDS and hepatitis. The corresponding cost and inefficiency of testing health care workers who have received an inadvertent needle strike result in considerable waste, which may particularly damaging to a health care facility which is striving for economy.
The following U.S. patents provide examples of syringes having a hypodermic needle which may be shielded after use to prevent an accidental needle strike:
U.S. Pat. No. 2,571,653, Oct. 16, 1951; PA1 U.S. Pat. No. 4,356,822, Nov. 2, 1982; PA1 U.S. Pat. No. 4,425,120, Jan. 10, 1984; PA1 U.S. Pat. No. 4,631,057, Dec. 23, 1986.